Uniqueness in Characters

Getting a well-rounded character isn't really all that difficult.
It's getting the second and third and eighth well-rounded character that gives me trouble. Cause see, they like to mimic each other and play follow-the-leader and that really doesn't work when it comes to writing a book. (Hint: If two characters are identical in every aspect than one of them is unnecessary.) 
I used to have an even worse problem where not only all the characters in one book were alike, but all the characters in all my books were pretty much clones. The main character was always a slightly tom-boyish girl who loved being outside, liked animals, went barefoot, enjoyed reading, could cook, was homeschooled (if that was applicable to the world they lived in), had a deep bond with their family, they traveled, had brown hair, and they were all practically perfect...
This "same" character could fit into many different stories and time periods:
*Annah's story took place in a made up country where a little girl and her mean big sister traveled though a large forest looking for their extended family after their parents died. They ended up becoming part of a spy ring that printed Bibles and tried to get the royal family back on the throne after a bad guy took over and created a dictatorship.
*Rebecca's story took place about twenty years ago and she lived with her mom, twin sister, and younger brother. They were estranged from most of their extended family, but as time went on and clues were found, relationships were restored. There was also a huge mansion and wealthy heir who lived up on a hill and lots of flower gardens and the mom cleaned for the lady, but I don't remember the details. 
*Rosanna's story took place in modern day Ohio (I think), and was about a girl staying with her older sister and brother-in-law. She follows a decades-old treasure map, solves a mystery, and hangs out with family. 
*Natalya's story took place in the land of Turglar where she had to travel for weeks by herself in a dangerous country to pass on secret information to her grandfather who she hadn't seen since she was a baby. 
*Lydia's story took place in modern day USA and involved a mystery in a bookstore and traveling with parents for their job (which is totally cool). Plus, it was also about an adventure in a cave and getting trapped and all that good stuff. 

When I started WLHYL I decided to do away with my photocopied character and although I don't think it would be evident to most people, Madalyn is pretty much the opposite of those ^ characters. 
Madalyn: Isn't tomboyish at all, is indoors girl, doesn't particularly enjoy animals. She's kinda proper with how she dresses (barefoot? no thank you), doesn't read much except for work, can make basic foods but doesn't very often, and went to a Christian school (although she does end up getting tutored at home). She does have a deep bond with her family, travel, and have brown hair, though.  
There were a lot of other ways I made Madalyn unique as well that I hadn't even planned on. See, after I got into the story and really focused on who Maddie was, she began taking on her own personality. As I've gone through the editing stages, every once in a while I've stopped and looked at the book all squinty and thought That's not what Maddie would do! and then I change it. 
For instance Madalyn never says "I think" or "I guess" or any of those-types of second-guessing sentences. When she speaks it's with confidence (which, is kinda funny since one of her issues is being insecure with choosing music "over" the family business). Before this book it never even entered my mind to distinguish between characters by a simple thing like that. 
* * *What about you? How do you make your characters unique? Or, what kind of uniqueness do you like finding in characters? 
* * * Yay! Yay! Yay! It's time to pick a new country to spend this week in. This week we're going to go to: China!